Mechanical Estimating Services for HVAC, Plumbing and Piping

HVAC estimating covers air systems and the equipment that serves them. Mechanical estimating is wider. It brings together HVAC, plumbing, mechanical piping and often fire protection, which is how most commercial mechanical contractors bid.

Pricing these systems together matters because the gaps sit between them. Who connects the water heater? Who runs the condensate to the drain? Who supplies the pumps for the hydronic loop? A combined mechanical estimate answers these questions once, so nothing is priced twice or left out.

Larger buildings often have a central plant: chillers, boilers, cooling towers, pumps, expansion tanks and heat exchangers, connected by chilled water, heating water and condenser water piping. We list every piece of plant equipment from the schedules and take off the piping by size, material and joining method.

• Pipe by size and material, such as steel, copper, PVC or PEX
• Joining method: welded, threaded, grooved, soldered or press fit
• Valves, strainers, balancing valves and specialties
• Hangers, supports, seismic bracing and sleeves
• Pipe insulation and jacketing by size and thickness
• Flushing, cleaning, chemical treatment and pressure testing

Two jobs with the same pipe length can have very different costs. Welded steel pipe takes longer per joint than grooved or press-fit pipe, and large pipe needs more rigging and more people. We count fittings and joints by size so labor reflects how the pipe will actually be installed.

We start from standard mechanical labor units, similar to those published by MCAA, and adjust them for height, access, pipe size and repetition.

Mechanical estimates are where scope arguments start. We list who carries each of these items, based on the drawings and specs:

• Motor starters, VFDs and power wiring: mechanical or electrical
• Controls and building automation: mechanical, controls contractor or owner
• Fire sprinkler system: included or by a separate fire protection contractor
• Equipment pads, roof curbs and roof penetrations
• Testing, adjusting and balancing, and commissioning
• Utility connections outside the building line

We organize mechanical estimates by CSI Division 21 Fire Suppression, Division 22 Plumbing and Division 23 HVAC, or by your own system breakdown, such as plant, piping, air side, plumbing and controls. Each section has its own subtotal, so you can see where the money is and compare it with subcontractor quotes.

In hospitals and clinics, mechanical work often makes up a large share of the building cost, with medical gas, redundant equipment, strict air handling and many small piping connections. Schools and universities tend to have central plants, large air handlers and long piping runs between buildings. Industrial and process projects bring compressed air, process water and specialty piping with demanding testing requirements. Office buildings mix packaged rooftop systems with VAV distribution and modest plumbing.

Each type has a different balance between equipment, piping and labor. We review the documents with that balance in mind, so the highest-value items get the closest check.

• Which piping materials and joining methods do the specs allow for each system?
• Is equipment purchased by the owner, by the general contractor or by you?
• Who carries the sprinkler system, controls, TAB and commissioning?
• Are there seismic restraint requirements for piping, duct and equipment?
• Is there demolition of existing mechanical systems or work in an occupied building?

Every open question becomes a written assumption in the estimate, so scope is clear before you submit.

Once you win the job, the estimate becomes your buyout plan. Equipment schedules go to suppliers for final pricing, piping quantities by size and material become your material orders, and labor hours by system help you plan crew sizes and the schedule.

Because the estimate is organized by system and division, it also turns into a clear schedule of values for billing. When addenda or change orders arrive, you can update only the affected lines, compare the new cost with the original and send a documented change request to the general contractor.

Division 21, 22 and 23

The CSI MasterFormat divisions for fire suppression, plumbing and HVAC.

Hydronic system

A heating or cooling system that moves hot or chilled water through pipes.

Grooved piping

Pipe joined with mechanical couplings in rolled grooves instead of welding.

Scope split

The written agreement on which trade supplies, installs and connects each item.

TAB

Testing, adjusting and balancing of air and water systems after installation.

• A summary by division or system with subtotals
• Detailed quantities for equipment, piping, ductwork and fixtures
• Labor hours and material cost for every line
• A scope split list and clarifications for your proposal
• Excel workbook and PDF summary